Ariel Atom. Not something I would drive on the road...but 0-100km/h in 1.8s and the open frame meaning you never miss an apex translates very well to the track!
Not to mention that it'd probably blow everything listed here away, including that Veyron, with the possible exception of a long-distance drag race.
Though I'm feeling increasingly guilty at my fascination with petrol chugging cars...
Not that biofuel is much better, lol. But as an example of a car that puts out over 1000bhpwhen you fill it with bioethanol, the Koenigsegg CCX-R is really a lean, mean, green machine 8D